Exam Questions Papers - Engineering

Q1:

A communication channel with AWGN operating at a signal to noise ratio SNR >> 1 and bandwidth B has capacity C1. If the SNR is doubled keeping B constant, the resulting capacity C2 is given by

A C2 ≈ 2C1

B C2 ≈ C1 + B

C C2 ≈ C1 + 2B

D C2 ≈ C1 + 0.3B

ANS:B - C2 ≈ C1 + B

C = B log2[1 + SNR] C = B log2[SNR] C' = B log2[2SNR] = B log2 SNR + B log22 C' = C1 + B.